Spring-harrow-tooth holder



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P. A. SPIOER. SPRING HARROW TOOTH HOLDER.

No. 434,407. Patented Aug. 12, 1890;

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(No Model.) 2 Sheets-Sheet 2. P. A. SPIOER. SPRING HARROW-TOOTH HOLDER.

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UN TED STATES PATENT OFFICE.

PRATT A. SPIOER, OF NEW PHILADELPHIA, OHIO.

SPRlNG-HARROW-TOOTH HOLDER.

SPECIFICATION forming part of Letters Patent No. 434,407, dated August 12, 1890.

Application filed October 12,1888- Sen'al No. 287,943- (No model.)

To all whom it may concern:

Be it known that I, PRATT A. SPICER, a citizen of the United States, residing at New Philadelphia, in the county of Tuscarawas, State of Ohio, have invented certain new and useful Improvements in Tooth-Holders for Spring-Tooth Harrows, of which the following is so full, clear, and exact a specification as will enable others skilled in the art to which my invention appertains to make and use the same, reference being had to the accompanying drawings, in which Figure l is a perspective view of my improved tooth-holder, showing a tooth in position and a portion of the harrow-frame in dotted lines. Fig. 2 is a longitudinal vertical section through the middle of my improved tooth-holder, showing the beam to which it is attached in cross-section and the tooth in'full side View. Fig.3 is a plan view of my improved holder with the follower removed. Fig. 4 is a vertical section of my improved holder in the plane a: 00 of Fig. 3. Fig. 5 is a vertical section of a harrow-tooth and holder constructed in accordance with my invention.

One of the objects of my invention is to provide a tooth-holder which shall present a seat to the back surface of the tooth, where it is mostefficacious.

Another object of my invention is to provide a tooth-holder in which the sides of the teeth shall be clipped by the walls of the holder and effectually prevented from turning in any plane.

Another object'of my invention is to provide a tooth-holder which shall hold and support the tooth most effectually with a given amount of material used.

Another object of my invention is to provide atooth-holderwhich shall present a constantly-increasing support under increasing strains.

Another object of my invention is to provide a tooth-holder which shall so twist the tooth when clogged as to immediately free it. To these ends my holder is constructed as follows: The seat A is composed, primarily, of a curved bottom 13. Onthe inside of this botto an exterior rib D, which is designed to stiffen the seat, the groove being made to save material expended in the raising of the rib. Rising vertically from each side of the bottom 13 are the two side walls E, bent into corrugations, as shown at E. The corrugations correspond to interior recesses or vertical grooves 12 and to perforations a, designed to receive fastening bolts, as shown in Figs. 1 and 2. The follower G is provided with ridges b, and in which they slide in the adjustment of the teeth, as hereinafter explained. The follower is also hollowed out, as shown at c, Fig. 1, for the reception of onehalf the bolts J. On the bottom of the follower are transverse ridges g, which press directly upon the inner surface of the tooth, as shown in Fig. 2. The curvature of the seat is made to conform approximately to that of the tooth for a short distance from its blunt end, but beyond a point about three inches from this end it falls away slightly from the tooth, as shown at K. The extreme edge of the lip is curved, as shown at L, for the purpose hereinafter set forth.

In placing the tooth, its rear surface near the butt is presented to the inner surface of the seat. The follower is then slid into place and the bolts run through the channels a, the rounded bolt-heads abutting against the rims a at the under openings of these channels. The upper'ends of the bolts are run through proper holes bored in the beam above and the nuts "h screwed tightly down. This completes the placing of the tooth and it is ready for operation. The under ribs of the follower press tightly upon the tooth, fixing it in the holder, while the walls E of the holder conline within certain limits the tooth and prevent lateral swerving of the same.

The peculiar construction of the holders has the following advantages: When the end of the tooth strikes a stump or firm stone, it will sometimes strike so flatly as to hold permanently and cause, in the ordinary construction, a breakage of the tooth. In my improvement, when such direct catching occurs, the tooth bends back as the harrow advances, gaining additional support all the time by bearing upon a fresh surface. If the obstacle be of such a nature that it will not yield even under this excess of elasticity,

the tooth is forced to abut upon the lip L; but this lip being curved, as shown, the tooth only strikes it at one point, and further pressure causes the tooth to twist in its length to one side or the other as its surface is pressed against the curved lip. This twist is transmitted along the tooth, which is turned to one side, slipping away from the obstruction, when the tooth is free to resume its normal working position by its own elasticity.

The simple attachment of my holder makes it very easy to adjust the tooth to any length and inclination required. The nuts are loosened and the tooth pulled or pushed by hand until in the proper position, when the nuts can be tightened again and the tooth secured. Under some circu Instances, Ifind it convenient to insert a supplementary strip of steel between the seat and the surface of the tooth, which is long enough to afford extra support to the anterior surface of the tooth.

The corrugations E in the sides and the rib D on the bottom of my holder lend a strength which is very great for a given amount of material, thus saving expense. The groove in the bottom also causes a saving of material, as does that in the under side of the follower, since the ribs 9 are abundantly strong, and it is a well-known law of friction that it is independent of the bearingsurface.

It will be understood that the peculiar construction of tooth and holder cause the former to move down at the front of the holder, whereas the holders heretofore in use and the teeth employed operate in an opposite manner.

It is evident that many minor details of construction may be modified without dc parting from the spirit of my invention; and I do not wish to limit myself strictly to the details described above.

Having now described the objects, uses, and advantages of my device, what I believe to be new, and desire to secure by Letters Patent, and what I therefore claim, is

1. A harrow-t-ooth holder having a curved and grooved bottom, in combination with an imperforate follower fitting between said sides, substantially as described.

2. A harrow-tooth holder having a curved bottom and provided with corrugations in its sides corresponding to interior bolt-holes, in combination with an imperforate grooved follower fitting between and within said sides of the holder, and bolts for extending through said grooves for holding the follower in place, substantially as described.

3. In a harrow-tooth holder, the ribbed and grooved curved seat, and sides having exterior corrugations corresponding to interior bolt-holes and grooves, in combination with bolts and nuts and a follower provided with grooves supplementing said bolt-holes, and ribs sliding in said grooves, substantially as and for the purposes specified.

4:. In a harrow-tooth holder, the ribbed and grooved curved seat, and sides having exterior corrugations corresponding to interior bolt-holes and grooves, in combination with bolts and nuts, and a follower provided with grooves supplementing said bolt-holes, vertical ribs sliding in said grooves, and transverse ribs on its under surface, substantially as specified.

5. A harrow-tooth holder having acurved solid bottom and sides forming a casing for the follower, in combination with a follower fitting between and within said holders and provided with transverse ribs on its under surface, substantially as described.

6. I11 a harrow-tooth holder having a curved bottom and sides forming a casing for the follower, and imperforate follower fitting be tween and within said holder and having transverse ribs on its end surface, in combination with bolts and nuts for fastening said holder to said harrow.

7. In a harrow, a curved spring-tooth, in combination with a holder having a seat curved to conform approximately with apart of the surface of said tooth and falling away a slight distance from the anterior portion of said tooth and provided with a projecting end. which arrests the forward movement of the tooth and changes the curve of it, substan tially as described.

8. In a harrow, a curved spring-tooth, in combination with a holder having a seat curved to conform with a part of the surface of said tooth and falling away from the anterior portion of said tooth, and an imperferate follower having ribs on its bearing-surface, substantially as described.

9. In a harrow, a curved spring-tooth, in combination with a holder having a seat which conforms approximately with a part of the surface of said tooth, and a lip falling away from the anterior portionof said surface and having a curved edge, substantially as and for the purposes specified.

10. In a harrow, a beam and curved springtooth, in combination with a seat curved to conform approximately with a portion of said tooth and a lip:falling away from its anterior surface, sides provided with corrugations corresponding to interior bolt-holes and grooves, a follower having vertical ribs and grooves, and transverse ribs and grooves bearing against said tooth, and bolts and nuts securin g said seat-walls and follower to said beam, substantially as described.

11. In a harrow,-a curved spring-tooth and beam, in combination with a seat curved to conform with a portion of the surface of said tooth and a curved edged lip falling away from its anterior surface, sides provided with corrugations corresponding to interior boltholes and grooves, a follower having vertical ribs and grooves and transverse ribs and grooves bearing against said tooth,and bolts and nuts securing said seat-wa1ls and follower to said beam, substantially as and for the purposes specified.

12. A barrow-tooth holder having its bottom curved upwardly from its rear to its front end, as shown, in combination with a follower located at the rear of said holder, and the 5 barrow-tooth located within said holder immediately beneath and between said follower and the holder.

13. A barrow-tooth holder having its bottom curved upwardly from its rear to its front 10 end, as shown, and having vertical sides, in combination with a follower located atthe rear of said holder and provided with transverse ribs on its under surface, and the harrow-tooth located beneath and in contact with said follower.

In testimony whereof I affix my signature in the presence of two witnesses.

PRATT A. SPICER.

YVitn esses H. T. S'rooKwELL, SILAS COMPTON. 

